Improvement in apparatus for feeding furnaces with fuel



GEORGE F DEACON -2 Sheets SheeH, Improvement in- Apparatus for Feedingfurnace with Fuel.

Patented June 20,1871

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Improvement in Apparatus for Feeding Furnaces with Fuel.

Patented June 20,1871- UNITED STATES PATENT OEEIoE.

GEORGE FREDERICK DEAOON, OF LIVERPOOL, ENGLAND, ASSIGNOR TO DILLWYNSMITH, OF BURLINGTON COUNTY, NEW JERSEY.

IMPROVEMENT IN APPARATUS FOR FEEDING FURNACES WITH FUEL.

Specification forming part of Letters Patent No. 116,165, dated June 20,1871.

To all whom it may concern:

Be it known that I, GEORGE FREDERICK DEAOON, of Liverpool, in the countyof Lancaster, in England, civil engineer, have invented certainImprovements in Apparatus for Feeding Furnaces with Fuel, of which thefollowing is a specification:

N atnre and Object of the Invention.

Description of the Accompanying Drawing.

Figure 1, Sheet 1, is a front view of a doublefiue boiler with myinvention applied to the same Fig. 2, a front view of a single-flueboiler with the apparatus attached 5 Fig.3, a side view of Fig. 2; Fig.4, Sheet 2, a plan view of Fig. 2; Fig. 5, a sectional plan on the line1 2, Fig. 2; Fig. 6, an enlarged sectional view of part of the apparatusand of the furnace and boiler to which it is attached; Fig. 7, a planview of the propelling-fans detached from the apparatus; Fig. 8,'asection on the line a a, Fig. 7 5 and Fig. 9, a section on the line y y,Fig. 8.

General Description.

In order that my improvements may be fully understood, I- will firstdescribe briefly the machine or apparatus upon which my saidimprovements are founded.

This machine was constructed with a hopper threw it into the furnaces.These fans were fixed on the lower ends of vertical shafts, extending tosome height above the boiler-front, in order to be clear of the hopper,and were driven by means of pulleys on the upper ends of these shafts.

I retain the use of the hoppers and fans, but instead of thecrushing-rollers, with the numerous toothed wheels and worms, which wererequired to drive them, and which constituted the most objectionable andtroublesome feature of the original machine, I prefer to use a screw orworm of any form, placed either vertically, horizontally, or obliquely,one end of such screw or worm being in communication with the hopper,the other end with the box containing the fans. Sometimes I use a'screwwith several threads of long pitch revolving horizontally in the bottomof the hopper, which, in this case, is placed directly over the fans.This screw has a shearing and crushing effect on the coal, reducing itto a small size, and metering it and delivering it to the fans. But bypreference I place the hopper a little to one side of that portion ofthe fan-box into which the coal is delivered, as shownin the drawing,where A represents an ordinary single-flue boiler; B, a frame forsupporting the feeding apparatus, secured at its opposite ends to theshell of the boiler O, the hopper and D, the fan-box. I connect thebottom of the hopper with an aperture, a, in the fan-box, for admissionof the coal to the fans, by a horizontal funnel or cylinder, F, in whichis arranged to turn a deeply-cut screw or worm, Gr, nearly equal indiameter at the fan-box end to the internal diameter of the cylinder,but tapering uniformly to a smaller diameter at the hopper end, thatportion of the screw directly beneath the hopper being merely a shaftwith a very shallow thread. This form of screw is preferable for tworeasons: First, thesmaller portion of the screw, working in the bottomof the hopper, or in a chamber communicating therewith, produces aslight but constant motion of the fuel from the hopper in a sloping heapalong the cylinder, extending further from the hopper than the naturalangle of repose of the fuel, and rendering the quantity of fuel carriedon during a given number of revolutions constant for different qualitiesof fuel. Secondly, the increasing size of the helix insures in itsrevolving motion the crushing of any lumps of coal or other fuel largerthan the pitch of the screw. To facilitate the production of this resultthe bottom of the cylinder, in which the tapered portion of the screwworks, may be corrugated longitudinally. Toward the end of thescrewcylinder there is an opening, I), communicating with the case orbox D, in which the fans H and H revolve. This opening I) may be placedat the bottom, end, or side of the cylinder; but I prefer to place it atthe side, and to lift the coal to it by projections or pins 0 on thescrewshaft. This causes the coal to fall over the edge parallel to aline joining the fan-centers, and renders the feed to the two fansequal. (See Figs. 1 and 6.) The screw may be driven by a single worm andwheel, d, which constitutes the only toothed gearing in the apparatus.When two fires are sufficiently close together, as in the double-flueboiler shown in Fig. l, I generally place the hopper between and use aright-and left-handed screw to carry the fuel from the hopper to thesaid fires. In this case a single worm and wheel is all the gearingrequired for the furnaces.

In the original machine a considerable quantity of coal fell between thehorizontal fans and onto the bottom of the fan-box. This coal,continually increasing, was pushed over the edge of the box onto thefront of the furnace and heaped upon the dead-plate. I remedy thisdefect by the use of a plate, bar, or deflector, J, Fig. 7, havingcurved and inclined sides, and corresponding in form with the spacebetween the two fans, which plate being fixed across the under part ofthe opening a, from which the coal falls, and above the fans, preventsthe coal from falling elsewhere than on the two fans; and with this Icombine a plate or slide, J, for increasing or diminishing the opening aso as to alter the position of the falling coal from one part of thefans to another, and thus adjust the uniformity of its distribution overthe grate-surface.

In the original machine a difficulty was experienced by the accumulationof coal-dust in the space between the fan-box bottom and the bottomplates of the revolving fans. I obviate this by casting onto thefan-bottom a spiral rib or vane, c, Fig. 7, which, working in thisspace, prevents any substance from entering or accumulating.

In the old machine the crushing or meteringrollers were geared from oneof the fan-shafts, so that to change the speed of these rollers it wasrequisite to change the speed of the fans also.

In my improved apparatus the worm-shaft receives its motion from one ofthe fan-shafts K; but I use conical pulleys i i, or other suitablemeans, for the purpose of varying'the relative velocities of the shafts,so that the speed of the mitering-screw may be altered without changingthe speed of the fans.

Instead of arranging the driving-pulleys above the hopper, as shown inthe drawing, I frequently render the whole apparatus more compact byshortening the fan-shafts and placing the said pulleys as low down aspossible, the fan-shafts in such case having both their top and bottombearings in one bracket, which is bolted to the fan-box or frame B.

It will be evident that my invention can be applied to furnacesgenerally, whether intend ed for generating steam or for other purposes,as well as to furnaces of the character illustrated in the drawing.

Claims.

1. The combination, with the hopper and fueldistributing fan, of a screwor worm, revolving within a cylinder or trough and conveying the fuelsubstantially as herein described.

2. The combination, substantially as herein described, of the hopper orother receptacle for the fuel, fans, or vanes, by which the said fuel isprojected into the furnace, and a screw, tapered, as and for the purposespecified.

3. The opening b, close to one end of the screw-cylinder and above thelevel of the bottom of the same, in combination with pins or projectionsc on the screw-shaft, for the purpose of lifting the fuel and pushing itinto the said opening.

4. The adjustable deflector J J, arranged and operating in combinationwith the fans and with the discharge-opening a, substantially in themanner described.

5. The spiral vanes a, cast on or secured to the bottom of thepropelling-fans, for the purpose specified.

6. The combination of the feed-screw, the feeding-fan or fans, theconical pulleys t i on the driving-shafts of the fan and feed-screw, andtheir adjustable strap, the whole being arranged as described, so thatthe speed of the feed-screw may be increased or diminished withoutaltering that of the fan, as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GEOBGE FREDERICK DEACON.

Witnesses:

CHAS. E. STEVENS, JNo. PHILLIPS.

